Macrophages were collected by bronchoalveolar lavage (BAL) from patients with various types of interstitial pnuemonitis (i.e., alveolitis) characterized by major lesions in the alveolar wall. These cells were then examined by light and electron microscopy. In addition, the effects of BAL macrophages were evaluated by various methods, such as PHA-stimulated proliferative T cell response, and PWM-induced immunoglobulin production of B cells. Macrophage function was also tested in terms of presence of antigens, phagocytosis and SRBC rosette formation mediated by IgG-Fc or C3 receptors, NBT reduction, and oxygen consumption. Furthermore, BAL-lymphocytes were examined in order to determine the percentages of activated T cells and activated B cells. These results all revealed that both macrophages and T cells were highly activated in granulomatous lung diseases including hypersensitivity pneumonitis, sarcoidosis, and chronic beryllisis, but not in idiopathic interstitial pneumonitis and interstitial pneumonitis with collagen disease, in which marcophages and B cells, rather, were highly activated.
These findings suggest that interstitial pneumonitis might be classified into two groups, one being “T lymphocyte alveolitis” and the other, “B lymphocyte alveolitis”.
